Wireless Internet Quiz questions

(MRN) The scrambling code in UMTS is used for further increasing the processing gain in addition to the spreading code. True. False.

(MRN) In 4G, the MME includes a DHCP server for assigning the IP address to the UE during the basic bearer activation. True. False.

(MRN) The X2 interface of 4G is used for exchanging measurements collected by UE in the case of coordinated handover. True. False.

(MRN) In 4G the access network GTP-U tunnel has IP addresses of the end points that are the UE and the S-GW and is reconfigured during each handover. True. False.

(MRN) In 4G, the number of PRBs per slot depends on the bandwidth available on the carrier. True. False.

(MRN) In a UMTS base station, if 28 codes with SF = 64 are in use, the number of available orthogonal codes with SF = 256 is 72. True. False.

(MRN) In 4G, the GTP-C protocol is used for exchanging signaling messages between MME and S-GW. True. False.

(MRN) In 4G, the IP addresses of transport IP packets exchanged on the S5 interface are those of the P-GW and S-GW. True. False.

(MRN) In 4G, the UE transition from RRC-CONNECTED to RRC-IDLE is triggered when the new traffic is received. True. False.

(MRN) In 5G, the functionalities of UPF include all the functions that in 4G are performed by P-GW and S-GW. True. False.

(MRN) In a HSUPA service, the UEs make use of dedicated channels with mutually orthogonal codes. True. False.

(MRN) In 4G, the GTP-U tunnel over the S1 interface is always modified during handover. True. False.

(MRN) In 4G, the number of resource blocks per slot is independent on the bandwidth of the radio interface. True. False.

(MRN) In MIMO systems, the "rank" associated to a UE defines the minimum capacity multiplication factor achievable with spatial multiplexing. True. False.

(MRN) In Circuit Switching (CS), fall back is a mechanism for routing a telephone call using 4G instead of using 2G or 3G. True. False.

(MRN) In 5G architecture, packet forwarding in the user plane between RAN and Core Network is based on a new tunneling protocol. True. False.

(MRN) MU-MIMO in 4G and 5G systems allows to serve one user at a time in each cell. True. False.

(MRN) In 4G, the UE state transition from RRC-CONNECTED to RRC-IDLE is riggered by the user. True. False.

(MRN) In 5G, the default router for the user IP layer changes depending on the user position. True. False.

(MRN) In 5G disaggregated architecture the near-real time Radio Intelligent Controller controls RUs, DUs, and CUs with a SDN like approach. True. False.

(MRN) In MIMO systems the maximum number of parallel streams is equal to the maximum between the number of transmitters and the number of receivers if the channel matrix has maximum rank. True. False.

(MRN) VoLTE is a system for using packet switched voice circuits in 4G networks. True. False.

(MRN) In 4G, The UE state transition from RRC-connected to RRC-idle is triggered by inactivity timers. True. False.

(MRN) In 4G, the default router for the user IP layer is the PGW. True. False.

(MRN) In MIMO systems the rank is used to characterize the number of antenna elements. True. False.

(MRN) In MIMO systems the maximum number of parallel streams is equal to the maximum between the number of transmitters and the number of receivers if the channel matrix has maximum rank. True. False.

(MRN) In LTE the attach procedure activates the RRC connection only. True. False.

(MRN) The GTP-C protocol in mobile packet services provides tunnels for user traffic. True. False.

(MRN) In CS mobile terminated call setup, the MSRN is used for routing call to GMSC. True. False.

(MRN) Open RAN architecture is based on a software controller integrated in each base station. True. False.

(MRN) Location management in 4G and 5G systems is alway on cell basis and location areas are no longer used. True. False.

(MRN) In 4G, the IP addresses of transport IP packets exchanged on the S1 interface are those of the P-GW and S-GW. True. False.

(WI) Proactive routing protocols perform better than reactive protocols in highly dynamic scenarios. True. False.

(WI) According to Little’s law, the average number of packets in a queue is equal to the average waiting time multiplied by the arrival rate in that queue. True. False.

(WI) 802.11 frames are all subject to an error control based on ACKs. True. False.

(WI) UDP suffers the same issues of TCP when used on wireless media. True. False.

(WI) It’s a good practice to always use the RTS/CTS mechanism. True. False.

(WI) 802.11ad (WiGig) is based on very low frequency (sub-GHz) transmissions. True. False.

(WI) An 802.11 data frame is retransmitted indefinitely until the corresponding ACK is received. True. False.

(WI) The Listen Interval parameter is fundamental for 802.11 DCF access with Listen-Before-Talk (CSMA-CA). True. False.

(WI) In the Aloha single buffer model, the number of full buffers remain the same if a single new packet is generated (1 new arrival) and no retransmissions are attempted. True. False.

(WI) The TCP receiver window and in general flow control is greatly affected by random losses due to wireless channels. True. False.

(WI) 802.11ad/ay (WiGig) has the same beacon transmission process than legacy 802.11. True. False.

(WI) Polling should be preferable over random access when delay needs to be minimized. False. True.

(WI) De-authentication attacks can be mitigated with simple techniques implemented on the attacked stations. True. False.

(WI) The long-lived TCP model with losses can be used for modeling the download of text-only web-pages. True. False.

(WI) Loss differentiation algorithms are used to understand if a segment loss is due to a channel error or congestion. True. False.

(WI) A Bluetooth piconet with 4 slaves and 1 master can be modeled as an exhaustive polling system with 8 stations. True. False.

(WI) Physical carrier sensing allows to eliminate all types of collisions. True. False.

(WI) MAC randomization can be used during data transfer to protect the privacy of a user. True. False.

(WI) Loss differentiation algorithms are used to understand if a segment loss is due to a channel error or congestion. True. False.

(WI) A Bluetooth device can participate as master to more than one piconet. True. False.